Are boiling water taps worth it? Pros, cons and fitting

How a boiling water tap works

A boiling water tap is two parts: the tap on the sink and a small insulated tank in the cupboard below. The tank is fed from the cold mains, heats the water electrically and keeps it at close to boiling. When you use the boiling function, water is drawn from the tank and out of the spout. Most models combine it with normal hot and cold mixer water, so one tap replaces your existing kitchen tap.

Some tanks are pressurised and store water under mains pressure; others are vented and open to the air. The design affects what else needs fitting, such as a pressure-reducing or expansion kit supplied by the manufacturer, and how the tank is installed and maintained. Many systems also include a filter, either inside the tank assembly or as a separate cartridge, to reduce scale and improve taste.

There are also taps that give filtered chilled or sparkling water from a second unit. They are the same idea with more equipment under the sink, and more to maintain.

The advantages

Households that use the kettle all day, such as people working from home or large families, feel the benefit most. It is also popular in kitchens being refitted, when the tank and socket can be planned into the sink cabinet from the start.

• Hot water for drinks, pasta or blanching vegetables in seconds, without waiting for a kettle
• You run exactly the amount you need rather than boiling a full kettle
• A clear worktop, which matters in small London kitchens
• One tap can replace both the kitchen tap and the kettle
• Filtered water from the same spout on many models, which some people prefer for taste

The disadvantages

None of these rules a boiling water tap out, but they are worth weighing honestly. If you use the kettle three or four times a day, the convenience may not justify the cost and the servicing.

• The tap and tank cost many times more than a good kettle, and fitting adds to that
• The tank keeps water hot all the time, so there is a standing electricity use even when you are not using it
• It takes a large share of the sink cupboard, alongside the waste, isolation valves and any waste disposal unit
• Filters or descaling are needed regularly, particularly in hard water areas like London
• Repairs to the tank are often model-specific and may need the manufacturer's own service
• Near-boiling water from a tap is a real scald risk, especially with young children

Boiling water tap or kettle: how to decide

Ask yourself three questions. How many times a day do you boil water? The more often, the more a boiling water tap earns its keep. Is the kitchen being refitted? Fitting the tank, socket and tap as part of a new kitchen is much easier than squeezing them into an existing cupboard. And are you likely to be in the property for several years? A boiling water tap is an investment that pays back in convenience over time, not in a first winter.

If the answer to all three is yes, a boiling water tap is usually a good buy. If you rent, or the kitchen will be replaced in a year or two, a quality kettle is the sensible choice for now.

What you need before you buy one

Check these before ordering, because they decide whether the tap you like can actually be fitted in your kitchen.

Pressure and water hardness are the two that catch people out. Each model lists a minimum and maximum inlet pressure, and our guide to tap water pressure compatibility explains how to check yours. In London's hard water, scale shortens the life of the tank unless it is filtered or protected; our guide on whether a water softener is worth it covers the wider options.

• Space in the sink cupboard: measure the height, width and depth left after the waste trap, and compare it with the tank's installation drawing
• A socket in the cupboard: most tanks plug into a switched socket or fused spur under the sink; if there isn't one, an electrician will need to add it
• Water pressure within the model's stated inlet range
• A tap hole that suits the new tap, and a worktop or sink that can take it
• Hard water protection: a filter or scale protection suited to the tank
• Clearance around a dishwasher or waste disposal unit, if either shares the cupboard

What fitting a boiling water tap involves

The installation is mostly kitchen plumbing, done to the manufacturer's instructions. The old tap comes off, the new tap goes on with its supply hoses, and the tank is placed and connected to the cold supply, usually with an isolation valve and any pressure or expansion kit the model requires. The hot supply for the mixer side is connected as normal. The tank is then filled, powered up and flushed, and every joint is checked for leaks once it is hot.

Our guide on how to replace a kitchen tap covers the tap side of the job. The tank side is where mistakes are expensive: a wrongly fitted pressure kit, a kinked hose or a tank without enough ventilation space can all cause faults or void the warranty. Many manufacturers also ask for the product to be registered, and some need a qualified installer for their guarantee to apply, so check the terms before you fit one yourself.

If the kitchen sink is moving at the same time, plan the tank position and socket as part of moving a kitchen sink rather than as an afterthought.

Never disconnect a boiling water tank or open its connections while it is hot or powered. Switch it off at the socket, follow the manufacturer's instructions and let it cool before any work.

Looking after it once it is fitted

Keep to the filter or descaling interval the manufacturer gives, which is often shorter in hard water areas. A slow or spitting boiling function, a tank that takes longer to recover or water that tastes of scale are the usual signs that maintenance is overdue.

For faults, work out whether the problem is the plumbing around the tap or the tank itself. Leaking hoses and valves are ordinary plumbing repairs; a tank that will not heat is usually a manufacturer service matter. Our guide to boiling-water tap problems explains how to tell the difference and who to call.

Get a boiling water tap fitted

Loyal Plumbers fits kitchen taps and connects boiling water taps across London and inside the M25, as part of our kitchen plumbing work or on their own. Send us the make and model you have chosen, a photo of the inside of the sink cupboard and whether there is a socket in it. We will check the pressure, space and connections before fitting, and tell you if anything else is needed first.

Call 020 4652 8585 or send an enquiry, and we will book a time that suits you.